Tissue engineering is the science of design and manufacture of new tissues to replace impaired or damaged ones. The key ingredients for tissue engineering are stem cells, the morphogens or growth factors that regulate their differentiation, and a scaffold of extracellular matrix that constitutes the microenvironment for their growth. Recently, there has been increasing interest in applying the concept of tissue engineering to endodontics. The aim of this study was to review the body of knowledge related to dental pulp stem cells, the most common growth factors, and the scaffolds used to control their differentiation, and a clinical technique for the management of immature non-vital teeth based on this novel concept. (J Oral Sci 51, 495-507, 2009)

Adenoid cystic carcinoma (AdCC) and polymorphous low-grade adenocarcinoma (PLGA) have several common histological and clinicopathological features that may create diagnostic difficulties. In this study, 10 AdCCs, 8 PLGAs, and 5 normal minor salivary glands as a control group were selected. Sections prepared from each tumor were stained using the streptavidin-biotin system for seven marker antigens: carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), muscle-specific actin (MSA), vimentin, S100, p53, and Ki-67. Data analysis showed high expression of CEA, MSA and Ki-67 in AdCCs compared with PLGAs, although CEA expression was limited to luminal cells. Ki-67 was expressed in both luminal and non-luminal cells and MSA only in non-luminal cells. Vimentin and S100 showed stronger expression in PLGAs, the expression of vimentin was more noticeable, being focal and widespread. The immunoreactivities of EMA and P53 were not helpful for distinguishing between the two tumors, although the EMA expression pattern in AdCCs was limited to luminal cells, whereas it was present in both luminal and non-luminal cells in PLGAs. Thus, immunohistochemistry can be helpful for differential diagnosis of AdCC and PLGA, particularly that for CEA, vimentin, and Ki-67. (J Oral Sci 51, 509-514, 2009)

Dental anxiety is still prevalent, despite advances in treatment, and affects the utilization of health care services. The purpose of this cross-sectional study was to determine if patients with different degrees of dental anxiety and pain undergoing emergency dental care have different stress reactions as measured by salivary cortisol. Seventy three patients completed the modified dental anxiety scale (MDAS), and described any previous dental traumatic experience. Their socio-demographic characteristics were also recorded. They also rated pain intensity on a 100 mm visual analogue scale (VAS). A saliva sample was collected before the procedure, and analyzed by enzyme immunoassay. Thirty patients were dentally anxious and forty one complained of pain. In this sample, dental anxiety was not related to gender, age, educational level and family income; however, a previous traumatic event was related to dental anxiety. There was no association between salivary cortisol concentrations and gender or dental anxiety. Patients with pain showed higher cortisol levels. When gathering patient information, the dentist should note patients' negative dental experiences in order to provide more effective, less traumatic treatment. (J Oral Sci 51, 515-520, 2009)

Irf6 (interferon regulatory factor 6) is expressed in tooth buds and palatine rugae during development in the mouse. Here we report the first study to investigate whether IRF6 variation is associated with palatine rugae patterns in a population with sporadic tooth agenesis. Fifty-two individuals with sporadic tooth agenesis and their parents were studied. Palatine rugae were scored from casts available for a subset of 38 families. DNA samples were obtained from whole blood or saliva samples. Genotyping was performed using TaqMan assays. Linkage disequilibrium and transmission distortion analyses of the marker alleles were performed. Borderline results were obtained for IRF6 genetic variation and having primary rugae larger on the right side than on the left (rs20131633, P = 0.07; rs642961, P = 0.06) and having fewer than eight primary palatine rugae (rs20131623, P = 0.07). However, no specific pattern of tooth agenesis was associated with the palatine rugae patterns studied. Our data suggest that IRF6 may contribute to specific palatine rugae patterns in humans. (J Oral Sci 51, 521-526, 2009)

The purpose of this study was to investigate the effect of previous phosphoric acid etching on the dentin bond strength of single-step self-etch adhesive systems. Facial surfaces of bovine teeth were wet ground with #600 SiC paper. Adhesives were applied with and without previous phosphoric acid etching, and light irradiated. Resin composite was bonded to the adherend surface, followed by light irradiation and storage in water at 37°C. Four groups (n = 10) were made per adhesive system: with and without previous acid etching and with and without thermal cycling between 5°C and 55°C for 10,000 cycles. Specimens were tested in a shear mode at a crosshead speed of 1.0 mm/min. Two-way ANOVA and Tukey HSD test at a level of 0.05 were performed. The changes in dentin bond strengths were different among the adhesive systems tested. In all experimental conditions of this study, the dentin bond strength decreased or remained unchanged with previous acid etching. From the results of this study, previous acid etching might not be acceptable for increasing dentin bond strength of the single-step self-etch adhesive systems. (J Oral Sci 51, 527-534, 2009)

The complexity of rehabilitation for totally edentulous patients makes it necessary to devise treatment strategies that meet the patients' expectations in terms of function, esthetic, psychological, and social aspects. The aim of this study was to i) compare the satisfaction of edentulous patients who had been rehabilitated with implant-supported overdentures and fixed prostheses in the mandible, and ii) assess the technical aspects of the prostheses in relation to patient satisfaction. This was a cross-sectional study involving 30 patients, 15 of whom had been rehabilitated with implant-supported overdentures and 15 who had been treated with fixed prostheses. The patients answered the OHIP-EDENT questionnaire, validated for the Brazilian Portuguese language, to assess satisfaction. Also, patients underwent clinical examination to assess the condition of their prostheses. Statistical analysis using the Mann-Whitney U-test revealed no significant differences in satisfaction between patients with overdentures and those with fixed prostheses. Likewise, Fisher's exact test demonstrated no significant differences in patient satisfaction concerning the condition of the prostheses as evaluated by the prosthodontist. It was concluded that both types of prostheses were perceived as being equally satisfactory by edentulous patients, and that the condition of the prostheses did not influence individual satisfaction in terms of rehabilitation. (J Oral Sci 51, 535-543, 2009)

The objective of this study was to describe the self-perceived need for and utilization of dental care in Indonesia. Using secondary data from the Indonesian National Socio Economic Survey, 2006 (n = 1,107,594) and 2007 (n = 1,167,019), we estimated the proportion of perceived need for and utilization of dental care. Descriptive and multivariate logistic regression analyses were used to describe the perceived need for and utilization of dental care in different demographic and socioeconomic groups (based on age, gender, living standards, residence, macroregions, and health insurance entitlement) in Indonesia. Approximately only 2.33% and 2.28% of Indonesians reported a perceived need for dental care in 2006 and 2007, respectively. Dental care utilization increased from 0.65% in 2006 to 0.84% in 2007. Additionally, unmet need decreased from 72.04% in 2006 to 63.13% in 2007. Logistic regression analysis indicated that respondents aged 30-44 years, who were wealthy, and were insured had higher odds ratios in perceiving need for and utilizing dental treatment. The perceived need for and utilization of dental care among Indonesians was found to be low, and was influenced by various demographic socioeconomic factors. (J Oral Sci 51, 545-550, 2009)

Neovascularization in the stroma of a tumor plays an important role in tumor growth and the establishment of metastases. The present study examined the immunohistochemical expression of vascular endothelial growth factor receptor 2 (VEGFR2) in 34 cases of oral squamous cell carcinoma (OSCC). Moreover, the relationships between parameters of tumor neovascularization (count of VEGFR2-positive [+] cells and total size of vessel lumen [TSVL]) and those of histology (differentiation type and mode of invasion) were analyzed statistically. Immunohistochemical expression of VEGFR2 was localized in stromal cells at the tumor invasive front. The VEGFR2+ cell count around poorly differentiated tumors was significantly higher than that around well differentiated tumors (P = 0.032, one-way ANOVA). The TSVL around the well differentiated type was found to be significantly larger than that around the poorly or moderately differentiated type (P < 0.001, respectively; one-way ANOVA). With regard to the mode of invasion, the TSVL was significantly larger for lower-grade (Grades 1+2) than for higher-grade (Grades 3+4) tumors (P < 0.001, unpaired t-test). On the basis of our results, we suggest that vascular development at the invasive front of OSCC is governed by the following factors: the tumor cells themselves may induce hemangiogenesis in the adjoining stromal tissue; hemangiogenic activity is higher when parenchymal intercellular adhesion is looser and when the parenchymal area exposed to the stroma is greater; and the rate of blood flow is higher when parenchymal intercellular adhesion is tighter and parenchymal nests are larger. (J Oral Sci 51, 551-557, 2009)

This in vitro study compared conventional and digital radiographic linear measurements to determine the working length (WL) of curved canals with fine endodontic files. In total, 30 mesiobuccal root canals in molars were measured with a #06 K-file to a length 1 mm short of the apical foramen (WL1). Teeth were mounted in plastic blocks and standardized periapical radiographs were obtained by conventional and digital (Digora Optime®) radiographic methods with #06, #08 and #10 K-files positioned in WL1. Two independent and calibrated examiners performed the conventional measurements with a millimeter ruler, from the file stop to the file tip (WL2). For the digital images, examiners used the linear measurement tool on the Digora® software, in original mode (WL3). For comparison of WL1, WL2 and WL3, the Wilcoxon test (P < 0.05) was applied and the reproducibility of the measurements was assessed. There was no statistically significant difference between Wl2 and Wl3 for #06, #08 and #10 K-files (P = 0.341, 0.641 and 0.232, respectively), with an acceptable level of interexaminer agreement. The measurements of Wl2 and Wl3 were significantly (P < 0.05) larger than those of WL1. No difference was observed among the linear measures obtained with either radiographic method, which showed higher WL values than the direct measurements. (J Oral Sci 51, 559-564, 2009)

The aim of this study was to determine the impact of bethanechol administration concomitant to radiotherapy (RT) on oral mucositis, candidiasis and taste loss. We performed a secondary analysis of a previously conducted prospective randomized trial which evaluated the effect of bethanechol on salivary gland dysfunction before, during, and after RT for head and neck cancer (HNC), in comparison to artificial saliva. Mucositis, candidiasis and taste loss were analyzed in 36 patients. Mucositis was scored using the World Health Organization (WHO) method; candidiasis was diagnosed by means of clinical examination, whereas taste loss was assessed by the patients' subjective report of absence of taste. No significant differences were observed between groups in relation to frequency and severity of mucositis or frequency of candidiasis and taste loss. In conclusion, bethanechol does not appear to reduce the incidence of mucositis, candidiasis, and taste loss when administered during RT. (J Oral Sci 51, 565-572, 2009)

The protein composition of oral fluid is modulated by environmental factors and physiological states, i.e. chemical, mechanical and pharmacologic stimuli, pathologic conditions, and psychological stress. Secretory protein concentrations in samples of whole saliva (WS) from children were measured and the results were subjected to statistical analysis. Protein expression was determined using electrophoresis and Western blotting. Protein profiles of children were significantly different from those of adults (n = 50, P < 0.05). All samples of saliva from children contained a group of high-molecular-weight (>90 kDa) proteins, whereas fewer than 5% of samples from adults had comparable bands. The ratio of the regulatory subunits (RII) of type II protein kinase A (an enzyme that regulates secretion) to total protein was stable in children's saliva, but variable in saliva from adults. Alpha amylase (α-amylase), an enzyme that digests carbohydrates, was less degraded in WS of children than in that of adults. Gingival crevicular fluid of both children and adults did not contain α-amylase or RII. No significant gender-based differences were found, but Caucasian children had higher salivary protein levels than children with an African background. Saliva collection is rapid, painless, non-invasive, economical, and yields findings that are reproducible. Objective, biochemical monitoring of secretory proteins in oral fluid of children may reveal responses to stressful stimuli. (J Oral Sci 51, 573-580, 2009)

The purpose of this study was to determine the prevalence of odontogenic cysts at the Pernambuco School of Dentistry – Universidade de Pernambuco (Brazil) and compare this prevalence with other international studies. Data for the study were obtained from reports of patients diagnosed with odontogenic cysts between 1992 and 2007. Case records of patients who fit the Histological Classification of the World Health Organization (2005) were included. The following variables were analyzed: gender, age group, anatomical location, histological type and ethnic background. Odontogenic cysts accounted for 9.94% of all lesions biopsied throughout the study period. Mean patient age was 28.9 years and 57.6% of the patients were males (P > 0.05). Radicular cyst was the most prevalent histological type (52.2%), followed by dentigerous cyst (30.7%). Regarding ethnic background, 41.8 % of the patients were of African descent, followed by Caucasians and other ethnic groups (P > 0.05). The mandible was the most prevalent site of the lesions (56%). Odontogenic cysts appear to have a distinct predilection for the male gender, the second and third decades of life (P < 0.05) and are more frequent in the mandible. The removal of odontogenic keratocysts from the new WHO classification has not altered the order of the most prevalent cysts in the maxillofacial complex. (J Oral Sci 51, 581-586, 2009)

Exploration of the relationship between tooth dimensions, body size, and age is important in paleontology, forensic odontology and aesthetic dentistry. It is reasonable to speculate that tooth length is associated with stature since teeth contribute to facial height. This study aimed to determine whether there was an association between tooth length and stature and age in a sample of Sri Lankan Sinhalese. Extracted teeth of adults, whose age, sex and standing height were known, were used for measurements. The total tooth length (TTL), crown length (CL) and root length (RL) of permanent maxillary central (68) and lateral (67) incisors were measured using a caliper. Statistical analyses were performed with the software MINITAB version 14.0 (Minitab Inc, USA). Mean age and standing height were 47.81 yr and 152.15 cm, respectively. There was no significant correlation between stature and tooth lengths of incisors. However, age was found to have a significant correlation with RL, (r = 0.26, P < 0.05) and CL (r = -0.28, P < 0.05). Absence of an association between tooth length and stature indicated that the genetic linkage between tooth size and stature was weak, suggesting that determination of stature from tooth lengths is unwarranted. The association between tooth length and age indicates the importance of root length in age determination. (J Oral Sci 51, 587-592, 2009)

The aim of this study was to investigate the apical leakage of roots filled by three different gutta-percha techniques: lateral condensation, Tagger's hybrid and E&Q Master. Forty-two extracted single-rooted teeth were used. The coronal part of each tooth was removed and the root received biomechanical preparation using a 60-K file. The roots were randomly divided into three groups according to the technique of filling the root canal: Group I, lateral condensation; Group II, Tagger's hybrid; Group III, E&Q Master. The roots were submitted to dye leakage test with Rhodamine B for 7 days, using vacuum during the initial 30 min. The teeth were sectioned longitudinally and the leakage was measured in a linear fashion from apex to crown. Statistical analysis indicated that lateral condensation and E&Q Master techniques showed lower leakage than Tagger's technique (P = 0.0016). However, statistically no difference was found between lateral condensation and E&Q Master system techniques. (J Oral Sci 51, 593-599, 2009)

The purpose of this study was to compare the sealing ability of gray mineral trioxide aggregate (GMTA), white MTA (WMTA), and both white and gray Portland cement as furcation perforation repair materials. A total of 120 human mandibular first molars were used. After root canal obturation and preparation of furcal perforations the specimens were randomly divided into four groups of 25 teeth each. In groups A, B, C, and D furcation perforations were filled with WMTA, GMTA, white Portland cement, and type II Portland cement, respectively. Ten teeth were used as positive controls with no filling materials in the perforations and 10 teeth with complete coverage with two layers of nail varnish were used as negative controls. A protein leakage model utilizing 22% bovine serum albumin (BSA) was used for evaluation. Leakage was noted when color conversion of the protein reagent was observed. The controls behaved as expected. Leakage was found in the samples from group A (WMTA), group B (GMTA), and in the two other groups (white and gray Portland cement). There were no statistically significant differences between GMTA and WMTA or white and gray Portland cement, but significant differences were observed between the MTA groups and the Portland cement groups. It was concluded that Portland cements have better sealing ability than MTA, and can be recommended for repair of furcation perforation if the present results are supported by other in vivo and in vitro studies. (J Oral Sci 51, 601-606, 2009)

The surface roughness of dental restorative materials has a crucial effect on the health of dental and periodontal tissues as well as for the longevity of restorations. In this study we tested a glass ionomer restorative cement, two nanohybrid resin composites, a flowable resin composite and a silorane-based composite. Twenty cylindrical specimens of each material were prepared, cured, polished and instrumented with a sonic scaler (Alegra ST ZE-55 RM W&H, Austria). The mean surface roughness was recorded using a profilometer (SJ-201, Mitutoyo, Japan) at three stages: before scaling, after scaling and after re-polishing. Additional specimens were analyzed by scanning electron microscopy and back-scattered imaging. Data were examined statistically by analysis of variance (ANOVA) and post-hoc tests at a level of significance of P < 0.05. The profilometric measurements and the SEM evaluation showed that, in most of the materials tested, the surface roughness was significantly increased after sonic instrumentation. After re-polishing the specimens, the roughness values were decreased. Periodontal scaling should include polishing of restorations in order to overcome alterations in surface roughness. (J Oral Sci 51, 607-614, 2009)

Inhibition of the initial events occurring immediately after ischemia-reperfusion seems to be beneficial for reducing the extent of subsequent chronic neuronal cell injury. We investigated the effects of moderate hypothermia (32°C) commencing 30 min before ischemia on reactive hyperemia by measuring cerebral blood flow (CBF) with a laser-Doppler flowmeter at the initial ischemia-reperfusion stage (60 min) following 10 min of global cerebral ischemia in rats. In normothermia, CBF was increased to approximately 240% and decreased thereafter, although it remained at approximately 150% after 60 min of ischemia-reperfusion. In contrast, hypothermia increased CBF to more than 270% after ischemia-reperfusion, then recovered to the basal level within 30 min. The period of reactive hyperemia under normothermia tended to be shortened by pre-administration of an NMDA antagonist, in a manner similar to hypothermia. Furthermore, hypothermia inhibited the presence of cells with caspase-3-like immunoreactivity in the hippocampal CA1 sector after 8 h of ischemia-reperfusion. Our findings indicate that hypothermia tends to shorten the period of reactive hyperemia during the initial ischemia-reperfusion stage. This phenomenon may be partly associated with activation of NMDA receptors and a beneficial effect of hypothermia in resisting progression of the neurotoxic cascade in the first 8 h after ischemia-reperfusion. (J Oral Sci 51, 615-621, 2009)

The present study attempted to describe the distribution of the mineralized tissues that compose the cemento-enamel junction, with respect to both the different types of permanent premolars of males and females and the various surfaces of individual teeth. The cervical region of ground sections of 67 premolars that had been extracted for orthodontic reasons were analyzed using transmitted light microscopy to identify which of the following tissue interrelationships was present at the cemento-enamel junction: cementum overlapping enamel; enamel overlapping cementum; edge-to-edge relationship between cementum and enamel; or the presence of gaps between the enamel and cementum with exposed dentin. An edge-to-edge interrelation between root cementum and enamel was predominant (55.1%). In approximately one-third of the sample, gaps between cementum and enamel with exposed dentin were observed. Cementum overlapping enamel was less prevalent than previously reported, and enamel overlapping cementum was seen in a very small proportion of the sample. In any one tooth, the distribution of mineralized tissues at the cemento-enamel junction was irregular and unpredictable. The frequency of gaps between enamel and cementum with exposure of dentin was higher than previously reported, which suggests that this region is fragile and strongly predisposed to pathological changes. Hence, this region should be protected and carefully managed during routine clinical procedures such as dental bleaching, orthodontic treatment, and placement of restorative materials. (J Oral Sci 51, 623-627, 2009)

The present study evaluated the shear bond strength between an indirect composite material and zirconium dioxide (zirconia) ceramics after thermocycling. A total of 80 zirconia (Katana) discs were divided into five groups and primed with one of following agents: All Bond 2 Primer B (ABB), Alloy Primer (ALP), AZ Primer (AZP), Estenia Opaque Primer (EOP), and Porcelain Liner M Liquid A (PLA). An indirect composite material (Estenia C&B) was then bonded to the primed zirconia. One-half of the specimens (n = 8) in each group were stored in distilled water at 37°C for 24 h, and the remaining eight specimens were thermocycled 5,000 times before shear bond strength testing. Mean bond strengths before thermocycling varied from 10.1 to 15.6 MPa; bond strengths after thermocycling ranged from 4.3 to 17.6 MPa. The ALP group had the highest strengths after thermocycling; there were no significant differences among the PLA, AZP, and EOP groups. The bond strength values for PLA, AZP, EOP, and ALP did not decrease with thermocycling. The application of an acidic functional monomer containing carboxylic anhydride (4-META), phosphonic acid (6-MHPA), or phosphate monomer (MDP) provided durable bond strength between Estenia C&B indirect composite and Katana zirconia. (J Oral Sci 51, 629-634, 2009)

The purpose of this study was to evaluate the correlation and distribution of dental postgraduate residents, dentists and clinical training facilities in each prefecture to analyze the regional distribution and supply of dentists in Japan. The results were also compared with referential data for medicine. The coefficient of correlation between the dentist index and dental postgraduate resident index was r = 0.76 (P < 0.001) in 2006. The distribution (coefficient of variation) was greatest for the dental postgraduate resident index. The numbers of dentists per 100,000 population in prefectures with dental colleges were significantly higher in 1986, 1996 and 2006 for each comparison (P < 0.001). Coefficients of correlation between dentist index and dental postgraduate resident index were r = 0.65 (P < 0.01) in prefectures with dental colleges and r = 0.11 in those without dental colleges in 2006. The prefectures with high level of numbers of cooperative-type clinical training facilities had dental colleges. (J Oral Sci 51, 635-639, 2009)

Sebaceous adenoma of the salivary gland is a rare tumor comprising 0.1% of all salivary gland neoplasms and less than 0.5% of salivary adenomas. Histologically, sebaceous adenomas are benign neoplasms consisting of sebaceous cells arranged in nests forming acinar and duct-like structures. Oncocytic metaplasia may also occur in some areas. We describe a case of sebaceous adenoma in the submandibular gland. Under a presumptive diagnosis of sialadenitis/sialolithiasis, the patient was administered multiple courses of antibiotics; however, these were not effective. Excisional biopsy resulted in a diagnosis of sebaceous adenoma. A 1-year follow-up showed no recurrence. (J Oral Sci 51, 641-644, 2009)

Following a rape incident in an apartment in Japan, we were requested to perform a DNA analysis on a body fluid stain left on a bath towel to determine whether it could be attributed to the suspect. The acid phosphatase and prostatic-specific antigen tests confirmed it to be a seminal stain. Based on the DNA analysis by autosomal and Y-chromosome short tandem repeat (STR) systems, no inconsistency was found with the profile of the suspect with African ancestry. In this case, allele 21 of DYS390 at the Y-STR locus was examined, as it is reported to have a distinctly lower frequency in the Japanese population. Furthermore, the haplotype combinations of Y-STR at the DYS389I, DYS389II and DYS390 loci are powerful for personal identification, as these have not yet been found in the Japanese population. (J Oral Sci 51, 645-650, 2009)

Discrepancy in the labial gingival margin of the maxillary incisors poses a major aesthetic problem. Orthodontic extrusion can improve the aesthetic problem caused by gingival margin levels before restoration. In these case reports, orthodontic extrusion was performed with palatal circumferential supracrestal fiberotomy for improving the discrepancy of the labial gingival margin. Two years postoperatively, the position of the tooth and gingival margin remained stable. Orthodontic extrusion with palatal circumferential supracrestal fiberotomy was effective in improving the discrepancy of the labial gingival margin of maxillary incisors. (J Oral Sci 51, 651-654, 2009)

Ectopic thyroid gland is a rare phenomenon that appears most frequently in the cervical midline and very rarely in other sites such as the submandibular region. This article reports a painless, non-tender and firm thyroid tissue mass in the right submandibular region of a 29-year-old female patient. Physicians should consider ectopic thyroid tissue as a differential diagnosis of submandibular swellings and be aware that this ectopic gland is the only functional thyroid tissue in 70% of cases. (J Oral Sci 51, 655-657, 2009)

Long-term studies have indicated that alloplastic bone grafts composed of nonresorbable hydroxyapatite (NHA) are clinically stable and safe. However, our previous report suggested that NHA grafts may be an etiological factor for recurrent periodontitis in the absence of supportive periodontal treatment (SPT). We removed infected NHA from the root surface by flap surgery in two cases of recurrent periodontitis. After removal of the infected NHA, the inflammation subsided in these cases and they were clinically stable for several years. (J Oral Sci 51, 659-663, 2009)